What is the central core of an atom, composed of protons and neutrons?

What is the central core of an atom, composed of protons and neutrons?

• A. Atom
• B. Nucleus
• C. Element
• D. Mass number

Answer: (B)

The central idea is that the nucleus is the dense, positively charged center of an atom where protons and neutrons are packed together. This tiny region holds almost all of the atom’s mass, while electrons form a surrounding cloud and contribute only a tiny fraction of the mass. Protons give the nucleus its positive charge, neutrons add mass without charge, and the strong nuclear force holds these nucleons together. The other terms don’t describe the central part: the atom is the whole structure including electrons; an element is defined by the number of protons; and the mass number is the total count of protons and neutrons. So the central core composed of protons and neutrons is the nucleus.

The central idea is that the nucleus is the dense, positively charged center of an atom where protons and neutrons are packed together. This tiny region holds almost all of the atom’s mass, while electrons form a surrounding cloud and contribute only a tiny fraction of the mass. Protons give the nucleus its positive charge, neutrons add mass without charge, and the strong nuclear force holds these nucleons together. The other terms don’t describe the central part: the atom is the whole structure including electrons; an element is defined by the number of protons; and the mass number is the total count of protons and neutrons. So the central core composed of protons and neutrons is the nucleus.